Separating apparatus



May 22, 1956 H. R. BRAMEL 2,746,602

SEPARATING APPARATUS Filed April 20, 1950- 4 Sheets-Sheet l INVENTOR Hadley R. Brame/ BY ww w ATTORNEYS y 1956 H. R. BRAMEL SEPARATING APPARATUS 4 SheetsSheet 2 Filed April 20, 1950 INVENTQR Hadley R. Bramefi BY M wv-ffifiaw ATTORNEYS y 2, 1956 H. R. BRAMEL 2,746,602

SEPARATING APPARATUS Filed April 20, 1950 4 Sheets-Sheet 3 Fig. 5

INVENTOR Hadley R. Bmmel ATTORNEYS y 1956 H. R. BRAMEL 2,746,602

SEPARATING APPARATUS Filed April 20, 1950 4 Sheets-Sheet 4 INVENTOR Hadley R. Brame/ ATTORNEYS United States Patent SEPARATING APPARATUS Hadley R. Bramel, Los Angeles, Calif.

Application April 20, 1950, Serial No. 157,168

24 Claims. (Cl. 209-132) My present invention relates to improvements in separating methods and apparatus, and more particularly to improvements in the continuous separation of physical components of fluid suspensions such for example as dust bearing air and gases, mists, slurries, slips, pulps, juices, milks, emulsions, waste products and the like.

The separatory operations to which my present invention is adapted include classification of suspended solids according to size and densities, thickening or concentration of suspended materials, clarification of fluids, and various combinations of such operations as, for example, thickening together with clarification.

In my co-pending application Serial No. 126,188 filed November 4, 1949, now Patent No. 2,693,280, granted November 2, 1954, I have disclosed methods and apparatuses in which particles entrained in confined fluid streams are separated primarily by what I term a shearing eiiect which causes them to migrate in course of passage from regions adjacent the boundaries toward the center of the stream. In utilizing this effect separation is secured by splitting off the outer stream fractions from the main stream. As disclosed in said co-pending application in suspensions in which the densities of the suspended particles are greater than those of the suspending media, inertial eifects are developed which may be utilized to assist the shearing action or the shearing effect, in the separatory action, or made the predominating separatory action. Similarly where the densities of the suspended particles are less than those of the suspending media as for example oil droplets in water, and cream dispersed in homogenized milk the shearing action may be reduced to a negligible minimum and the separation entirely efiected by inertial means.

It is accordingly a primary object of the present invention to provide novel separatory methods and apparatus in which such inertial effects are primarily utilized for separatory purposes.

In industrial sections of the country, air pollution resulting from industrial processes discharging dust and mist into the atmosphere has become a major problem. Such dusts and mists are a major factor in the formation of smogs in areas such for example as Los Angeles and Pittsburgh which are deleterious to public health, comfort and welfare, and have a depressing effect on property values. In addition, in many cases, such for example as in milling operations, the manufacture of food and other industrial products, commercial products of substantial value are lost.

It is accordingly a further object of my present invention to provide novel low cost separatory methods and apparatus particularly adapted for highly efficient separation of dusts andmists from air and other gases in industrial processes, to thereby substantially reduce air contamination and recover commercially valuable constituents now lost or recoverable only at prohibitive costs.

In the handling of dust laden air and gases to which the present invention is particularly adapted I have 2,746,602 Patented May 22, 1956 found that strong electro-static eifects are developed which may hinder the efiectiveness of the separatory action and tend to cause accumulations of fine materials and dusts which under certain conditions may clog the apparatus. It is accordingly a further important object of my invention to utilize the inertial efiects of the suspended solid particles to minimize or prevent such accumulations by impacting and freeing adhering particles adjacent the gas outlet or take-0E zones.

A still further object of my invention is to provide combination mechanical and electro-static separatory methods and apparatus in which the electro-static effects developed due to flows in the apparatus are utilized and accentuated to improve rather than impair the efiectiveness of the separation.

In the methods and apparatus disclosed in said co pending application the separatory actions are efiected by splitting off outer layers of the stream of suspended material in a single splitting operation. In the separa tions efiected by the present invention I utilize successive splitting ofi of relatively shallow layers from the outer stream with resulting highly increased mechanical separating efiiciencies in simplified low cost apparatus in which I have been able to separate completely particles of as small as two microns in size, and to remove the major proportions of particle sizes down to one micron and less without utilization of electro-static separatory eifects. The provision of such methods and apparatus accordingly is a further important object of my invention.

Another object of the invention is to provide novel separatory methods and apparatus in which the degree of concentration of the removed material may readily be varied for purposes of classification, conveying or moving the separated product, and for other industrial purposes which will be readily apparent to those skilled in the art.

A still further object of the invention is to provide .novel separatory mechanisms and systems for dust removal and recovery systems in which breathable air is separated which may be recirculated to conserve room heating energy during cold weather.

Other objects of the invention will become apparent as the description of the preferred embodiments proceeds in connection with the accompanying drawings and from the appended claims.

As shown in the drawings:

Figure 1 is a longitudinal sectional view (with the core spider in elevation) of a preferred embodiment of my invention;

Figure 2 is asection taken along line 22 of Figure I;

Figure 3 is an enlarged fragmental view with the spider omitted, diagranunatically illustrating the apparent flows inertial separatory effects occurring in the form of invention illustrated in Figures 1 and 2;

Figures 4 and 5 are sectional views with the core spiders in elevation illustrating embodiments of my invention utilizing combination electro-static effects to the separation;

Figure 6 is a fragmental sectional view of a modification of the invention adapted for high capacity separatory operations;

Figure 7 is an end view of the form of invention shown in Figure 6; 7

Figures 8 to 12 inclusive are diagrammatic illustrations of various systems efiectively utilizing my invention.

The invention of Figures 1-3 In the embodiment of the invention illustrated in these figures, A indicates generally a separatory assembly to which a supply duct for the fiuid suspension is connected through a flanged cylindrical end section 20 to which the inlet end of a frusto-conical body section 22 is welded. A cylindrical volute collector section (generally designated B) formed of circular end plates 24 and 26 and a cylindrical outer wall section 28 Welded together, is welded to the outlet end of section 22. An outlet pipe nipple 30 is welded to 28 and provided with a union connection 32 for convenient coupling to a discharge line. Welded to plate 26 is a sleeve 34 in which cylindrical sleeve section 36 of the separatory core (generally designated C) is mounted for longitudinal adjustment. A seal ring 38 of any well known type is provided between sleeve 36 and the end wall 26.

Secured in sleeve 36 is a core spider formed of a central rod 40 having three equally spaced webs 42. The outer end of the rod 40 is rounded to reduce flow turbulence and to its other end a core plate 43 is removably secured by means of a countersunk head screw 44.

Spaced notches 46 are formed in the outer surfaces of webs 42, and mounted in these notches is a series of accurately spaced rings 48. Each ring 48 has outer concave peripheral surface 49, fiat surface 50 in a plane normal to its axis and a frusto-conical surface 52. Rings 48 are assembled in stacked and slightly spaced relation on webs 42 so that adjacent surfaces 50 and 52 form restricted annular diffusing passages for fluid from the space surrounding the rings into the core spaces between webs 42.

Spaced rings 48 extend from end plate 43 to throttling ring 54 (Figure l). Throttling ring 54 is mounted on webs 42 adjacent the supporting sleeve 36 and forms outlet orifice 55 with section 22 and has a frusto-conical surface 56 which forms an inner wall section of diffusing outlet passage 58.

The core assembly C may be adjusted axially to vary the concentrated discharge orifice area by changing the position of surface 56. The core assembly is locked in adjusted position by setscrcw 60.

Operation of the device Figures 1-3 In operation of the device, the suspension upon which the separatory operation is to be performed is pumped through section 20, passes around end plate 43 of the core assembly C and enters the space between section 22 and the core. In this space it passes successively over surfaces 49 of rings 48, and thin layers indicated by the arrows 62 in Figures 1 and 3 blowing over the surfaces 49 pass inward through the spaces between ring surfaces 50 and 52 into the spaces between webs 42 and out through end sleeve section 36 of the core. As the particles to be separated pass over the curved surfaces 49, the smaller particles follow the generalized path indicated by the dotted line arrow 64 and the heavier particles follow the generalized path indicated by the dotted line arrow 66 in Figure 3. At the outer upstream edges of the rings 48 formed by the surfaces 50 and the curved surfaces 49, vortices 70 are formed in which small dust particles bearing frictionally generated electro-static charges tend to settle on and to cling to each other and to the ring surfaces 49. The trajectory of the coarser particles is such however, that these particles impact the adhering finer particles and scour off the vortex regions, forcing the adhering electro-statically charged particles into the concentrated stream indicated by arrows 72.

The progressive decrease in sectional area between frusto-conical section 22 and the outer surface of core C is preferably such that a substantially uniform flow rate of the concentrated suspension outside of the core is maintained. Successive thin clarified layers of fluid are accordingly withdrawn from the stream flowing over the core with the result that the density of this stream increases until it reaches the outlet orifice at ring 54. The concentrated stream then passes out through passage 58 into volute B and is discharged from the volute through the passage 30.

The degree of concentration of the stream passing into volute B may be controlled by varying its amount either through shifting the sleeve 36 and ring 54 to vary the outlet orifice area ring 55 or by throttling outlet 30 by use of a throttling valve. Restriction of discharge from the volute with a given volume of total flow increases the amount of fluid passing into and through core C, with the result that lighter solid components can be forced through the core providing limited classification between such lighter components and the heavier components which pass into the volute B.

While the relative sizes and proportions of the device illustrated are by no means critical, and are subject to wide variation Within the selection of a person of ordinary skill in the art, I have by way of example in Figures 1 and 3, Which are scale drawings, given the important dimensions in an assembly found effective for the separation of products such as alfalfa dust, clay dust, and similar products at capacities of about .0 to .7 cubic foot of free air per minute per linear inch of peripheral core opening at a head loss of 3 to 5 inches of water.

With this embodiment of the invention separation of particle sizes as small as from between one and two microns may be economically effected from gaseous streams. To separate smaller particles completely requires a substantial energy input increase, and substantial increase in cost of the equipment.

The invention of Figure 4 Figure 4 illustrates an embodiment of my invention adapted for economical separation of sub-micron size particles. Its inertial separatory functioning and performance is the same as described for the embodiment of Figure l. The reference characters of Figure 1 have accordingly been applied to the similar parts of Figure 4.

In Figure 4 the equally spaced webs 42 support a helix 51 wound of stock having a cross-sectional form which may be identical with that of rings 48 of Figure 1. This method of fabrication may be regarded as interchangeable with the ring stack shown in Figure 1.

The embodiment of Figure 4 differs from that in Figure 1 principally by virtue of the addition of electrical devices for the purpose of assisting the inertial effects in separating very small particles. In Figure 4 the separatory core elements comprising central rod 40, webs 42 and end plate 43 are of electrically non-conductive material. Likewise throttling ring 54 is of non-conductive material.

Supported by spider structure 40 and 42 and inserted between end plate 43 and helix 51, is a cylindrical insulator having substantially the same diameter as helix 51. On the outer surface of 80 is a small diameter ionizing conductor 84 wound in a spiral with both ends anchored in 80 and one end with connection to high potential lead in cable 86.

Moderate potential lead in cable 88 is similarly connected to helix 51. The outer metal parts of the separator comprising parts 20, 22 etc., are electrically grounded in well known manner.

Operation of the device of Figure 4 The inertial functioning of this embodiment is similar to that of the embodiment of Figures 1, 2, and 3 and need not be here described in detail.

The electrostatic effects which are superimposed on the inertial effects will now be described.

Wire spiral 84 is either positively or negatively charged through lead wire 86 to a level of potential sufficient to cause heavy corona discharge with consequent ionization of the gas stream between 84 and 22. Since this space is effectively swept by ions all discrete particles in the area will be charged either positively or negatively and will tend to retain their charges in moving forward into the separatory region between 22 and 51.

Since surfaces 49 are charged by wire 88, the like charges between surfaces 49 and the streambourne particles repel one another causing relative motion of particles away from the separatory core C. Likewise since surface 22 is grounded and therefore'of opposite potential with respect to the charged particles an attractive force in the direction of this surface is exerted. It should be particularly noted that because of unshielded position and high degree of curvature, the downstream edges of surfaces 49 carry a high concentration of charge at a point where a strong repulsive effect will most effectively influence the trajectories of nearby particles and thereby aid in clean separation.

Since particles moving from the stream toward surface 22 will tend to cling to this surface, the optimum conditions for operating the continuous inertial electrostatic separator require a scouring action sufficient to prevent accumulation and this involves a proper balance between electrical and mechanical intensities readily determinable in each particular application.

The super-imposition of the electrostatic effect on the inertial effect attained in this fonn of invention is primarily useful in the complete separation of very small submicron particles with a reasonable energy expenditure.

Such separation solely by inertial effects would require relatively high energy expenditure, and more, bulky and costly apparatus.

The invention of Figure 5 1 The embodiment shown in Figure 5, as shown by use of like reference characters for similar parts, difiers from that of Figure 4 mainly in providing heavier electrical insulation for operation at higher electrical intensities in this embodiment. The frusto-conical body section 22 is of insulating material and to provide a steep potential gradient the outer cylindrical shell conductor 9d grounded through lead 92 has bcenadded to the form shown in Figure 5.

To illustrate the interchangeability of the ring and helix construction, a ring stack such as shown in Figure 1 rather than a helix structure such as shown in Figure 4 has been shown in Figure 5. Longitudinal conductor 93 in contact with rings 48 and supported by insulating web 42 illustrates a method for providing electrical contact between rings.

The operation of this embodiment is closely similar to that of Figure 4, the principal difierence being that higher electrical potentials both for ionization and for repulsion can be applied without electrical sparking and breakdown.

The invention of Figures 6 and 7 The invention illustrated in these figures operates generally in the same manner as that of Figures 1, 2 and 3. The close geometrical similarity can be visualized by passing an imaginary plane along the section A-A in Figure 6 and comparing the resulting sections with the upper half of Figure l.

in Figures 6 and 7 the parts corresponding to the ring stack of Figure l or the helix of Figure 4 are in the form of a grid-like panel structure designated generally as G and comprising evenly spaced bar elements 108 of sectional form which may be identical with that of rings 48 or helix 51. The individual bar elements 100 are welded or soldered'in place by transverse tie bars 101 and the rectangular panels so formed are keyed in position by strut W2, cleats lii i and ducts 136. As in Figures 1 to 5 inclusive the concave surfaces 49 in Figures 6 and 7 form the separatory boundaries of the stream of fluid suspension which enters from the left, as indicated by arrows 64, flows to the right in diminishing quantity as increments of classified fluid are shaved off between bar elements and enters thickened fraction discharge apertures r 6 interruption along the main duct 114 in which G is mounted, as indicated by arrows 62. Y

General functioning and advantages The foregoing specific embodiments of my invention make principal but, not necessarily exclusive, use of the inertial effects in contrast to the shearing effects noted. comparatively large masses of fluid, while moving with substantially uniform velocity, are diminished in volume by substantially uniform amounts with each increment of forward motion by a shaving ofli process along one or more of its boundaries. Along these boundaries there exists a significant shearing gradient diminishing in magnitude with increasing distance from the boundary. In the cases in which filamentary, flaky or light flocculent materials are being processed the repulsive action of the shearing efiect, tending to restrain such hydrodynamic shapes from regions of intense shear will operate to assist the separation, that is to keep the solids in suspension in the mainstream until it passes the separatory region and is discharged with the thickened fraction.

Among the important advantages attained by my invention in dust collection is that surges, both of pressure and of Weight of material, do not upset operation. By contrast, in cyclones where reentrainment of settled material is an ever present contingency, surges, even changes in wind direction, may be very upsetting.

A further important advantage is that stream velocities in my improved apparatus are generally higher than flame propagation of dusts, and there is only a small volume of dusty air in treatment at a given instant. This results in reduced fire or explosion hazard.

Ease of design of separators for specific flow rates and pressure drops is another important advantage. This is attained because the essential mechanism remains to the same scale. Accordingly for treatment of a given fiuid volume and pressure the number of linear inches of core aperture required .is easily assigned and the remainder of the design for specific application is simple.

My improved methods and apparatus are applicable to many purposes throughout the range of separatory problems. One of the most variable factors, particularly in dust collection problems, is the load of dust material per unit of air or gas volume. At one extreme is the process of air conveyance of materials in great quantity such as cement or flour and at the opposite extreme is the removal of dust traces from the air of public buildings and the like. Whereas primary separator-y apparatus of the foregoing types may be used interchangeably for such extreme cases, secondary removal or accumulation may be desirable in particular cases as illustrated by way of example in Figures 8 to 12 hereinafter described in detail.

A characteristic of most dust suspensions is that above a certain concentration they tend to flocculate and settle rapidly. Thus where the material comprising a dust suspension is concentrated to half its original volume the problem of its eventual accumulation is more than half solved. With my improved methods and apparatus it is usually possible in one pass to concentrate the dust to five percent, or even less of its original volume. Where the original dust loading is light, ellicient concentration to say one percent is feasible. In numerous cases these degrees of concentration are sufiicient to secure strong dust flocculation and the problem of accumulation is therefore materially lessened.

. Since the frictional losses in the separator occur mainly between inlet and clarified fraction outlet, and the pressure drop between inlet and thickened fraction outlet may be kept small, ordinarily substantial pressure for a secondary accumulation step is available. This pressure may be used in the various ways shown in Figures 8 to 12 hereinafter described to accumulate, filter or to convey the dust-bearing fraction. As examples of extreme applications the circuit system of Figures 8 or 9 may be used to convey cement whereas the circuit shown in Figure in which 128 is a filter or electrostatic collector may be used to accumulate small dust loads in ventilation systems.

The inventions of Figures 8-12 Figures 8 to 12 illustrate in schematic form several systems or flow circuits in which the separators illustrated in Figures 1 to 7 may be used to obtain various separatory effects. In each of the Figures 8 to 12 the characters A, B and C refer respectively to the exterior housings, thickened fraction volutes and separatory cores as hereinbefore described in connection with Figures 1 to 5. It will, however, be understood that symbols A, B and C of Figures 8 to 12 are intended also to signify the functionally similar apparatus of Figures 6 and 7, equivalent to those of Figures 1 to 5. Thus A and C of Figures 8 to 12 may be replaced by 114 of Figures 6 and 7 and B of Figures 8 to 12 may be replaced by 110 of Figures 6 and 7.

In each of the Figures 8 to 12 a pump or blower 116 is indicated which circulates the fluid to be separated. In each figure also a feed conduit 118 for conveying the fluid to the separator, a conduit 120 for discharging the clarified fraction of the separation and a conduit 121 for conveying the thickened fraction are provided.

In Figure 8 the fluid to be separated enters the low pressure side of 116 and is delivered to A through 118. The clarified fraction is discharged from the apparatus through 120. The thickened fraction is delivered by 121 to a secondary separator 122 such as a small cyclone or plenum chamber in which a substantial fraction of the concentrated suspension is dropped and, if desired, accumulated. The fluid exhausted from 122 is returned through conduit 124 to the low pressure side of pump 116 from whence it is recirculated through the separator A, B, C.

In Figure 9 primary circulating pump 116 is placed down stream of the separator A, B, C and circulates only clarified fluid. Imperfectly clarified fluid in relatively small quantity exhausted from accumulator 122 is returned through 124 and supplementary pump 126 to conduit 118 up stream of the primary separator A, B, C.

In Figure 10 pump 116, as in Figure 9, is located in the clarified fraction duct down stream from separator A, B, C. The thickened fraction is delivered by 121 to a secondary separatory device 128 which in certain cases may be a simple gravity, inertial, or cyclonic apparatus as in Figures 8 and 9, a filtration device containing bags or membranes, a small separator of electrostatic type, or a separator of the type disclosed in my copending application of even date herewith. In any case the small fluid residue exhausted from 128 and designated 130 is sufficiently clarified for discharge from the circuit.

Figure 11 represents a simple circuit in which dust bearing air or gas is drawn by hood 132 into pump 116 which circulates through 118 to A, B, C. Clarified gas is discharged through C while the thickened fraction may be conveyed by means of its residual potential and kinetic energy through relatively small duct 120 to a distant point of accumulation.

In Figure 12 the pump 116 is located in the clarified fluid duct down stream from separator A, B, C. This circuit illustrates a useful characteristic of the energy disposition in the operation of the separator, namely that potential energy above atmospheric pressure for conveying or further separation may be made available in B even when the separatory system is operated below atmospheric pressure.

The foregoing systems are adapted among other applications to the clarification and return of heated breathable air in industrial operations and ventilating systems to conserve heating energy, to the removal of ducts from exhaust products such as flue gases, to the recovery of materials such as flour or cement otherwise lost in processiug as air borne dust, and as a concentrator for use with pneumatic conveying systems.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by the United States Letters Patent is:

1. In a fluid suspension separator or classifier, a duet forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating core Within said duct and dividing said duct into an exterior portion connected to said inlet and said first outlet, and a central portion connected to said second outlet; perforations through the wall of said core; and transversely concave faced deflectors on the outside of said core, on the upstream side of said perforations, to deflect heavier particles away from said perforations while permitting lighter fractions to pass therethrough.

2. In a fluid suspension separator or classifier, a tube forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating core within said tube and dividing said tubes into an annular portion connected to said inlet and said first outlet, and a central portion connected to said second outlet, including a tubular assembly having an outer surface comprising a series of axially spaced transverse concave surfaces terminating in outwardly extending downstream lips, and inwardly extending passageways downstream of each lip, whereby lighter fractions pass to said central portion and to said second outlet and heavier fractions pass to said first outlet.

3. The apparatus described in claim 2 wherein said tube and said core are so shaped as to form an annular passageway of decreasing cross section between said inlet and said first outlet.

4. The apparatus described in claim 2 wherein said tube and said core are so shaped as to form a passageway of decreasing cross section between said inlet and said first outlet; and means for controlling the rate of flow through at least one of said outlets.

5. The apparatus described in claim 2 wherein said tube and said core are so shaped as to form a passageway of decreasing cross section between said inlet and said first outlet; means for constricting said first outlet; an annular chamber receiving the heavier fractions from said first outlet and of sufficient size to convert the kinetic fluid energy to potential energy; and an outlet from said chamber.

6. In a fluid suspension separator or classifier, a tube forming a passageway and having a fiuid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating core within said tube and dividing said tube into an annular portion connected to said inlet and said first outlet and a central portion connected to said second outlet, including a coaxial assembly of spaced rings each having an outer wall forming a transverse coneave surface terminating downstream in an outwardly extending lip; the spaces between adjoining rings forming passageways between said annular and central portions of said passageway; and means supporting said rings in said tube.

7. In a fluid suspension separator or classifier, a tube forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating core within said tube and dividing said tube into an annular portion connected to said inlet and said first outlet and a central portion connected to said second outlet, including a helically formed element extending axially of said tube, formed of a body having an outer surface concave in cross section to provide in effect a cylinder having a series of spaced transversely concave surfaces extending axially of said tube.

8. In a fluid suspension separator or classifier; a duct forming a passageway and having a fluid inlet at one end; a first outlet and a second outlet from said duct; and separating means between said inlet and said second outlet providing a series of spaced transverse elements having cross sections transversely concave on the side facing the suspension arriving from said inlet.

9. In a fluid suspension separator or classifier; a duct forming a passageway and having a fluid inlet at one end; a first outlet and a second outlet from said duct; separating means between said inlet and said second outlet providing a series of spaced transverse elements having cross sections transversely concave on the side facing the suspension arriving from said inlet; and means for imparting like electrical charges to the particles in the suspension and to said separating means.

10. In a fluid suspension separator or classifier, a tube forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating core within said tube and dividing said tube into an annular portion connected to said inlet and said first outlet, and a central portion connected to said second outlet; perforations through the wall of said core; andmeans for imparting like electrical charges to the particles in the suspension and to said fluid separating core.

11. In the apparatus described in claim 9, said duct being a non-conductor; and a grounded conductor surrounding said duct.

12. In a fluid suspension separator; an external housing; and core means within the housing and dividing the space within the housing into a first gas passage outside the core means and a second gas passage within the core means, said core means including a series of closely,

spaced elements, each element being generally quadrilateral in cross section and closely and substantially uniformly spaced from adjoining elements at their adjacent ends so that each element presents to said first gas passage a face from end to end several times as long as the spacing between elements, the downstream edge of each element projecting outwardly beyond the upstream edge of the same and adjacent elements.

13. In a fluid suspension separator; an external housing; and core means within the housing and dividing the space within the housing into a first gas passage outside the core means and a second gas passage within the core means, said core means including a series of closely spaced elements each having an outer face of concave shape exposed to said first gas passage with the downstream edge of the concave face projecting outwardly beyond the upstream edge of the concave face of the adjacent downstream element.

14. A fluid suspension separator as defined in claim 13 in which said closely spaced elements are each generally quadrilateral in section, with three plane faces of which two faces converge inwardly toward the second gas passage to provide between each two successive elements a passage of increasing cross section inwardly toward the second gas passage. 7

15. A fluid suspension separator as defined in claim 13 in which said closely spaced elements are a plurality of substantially uniformly spaced ring members.

16. A fluid suspension separator as defined in claim 13 in which said closely spaced elements are adjacent turns of a helix element.

17. In a fluid suspension separator; an external housing having fluid inlet and outlet openings; and means mounted in said housing and dividing the space therein into a plurality of independent gas passages for entering fluid and for separated lighter fractions, said means including a series of closely spaced separating elements each having a face of concave shape exposed to the entering fluid with the downstream edge of said concave face projecting outwardly beyond the upstream edge of the concave face of the adjacentdownstream element.

18. In a fluid suspension separator or classifier, a duct forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating'partition within said duct dividing said duct into a first portion connected to said inlet and said first outlet and a second portion connected to said second outlet, said partition including an assembly having a surface facing the suspension arriving from said inlet comprising a series of longitudinally spaced transverse concave surfaces terminating in outwardly extending downstream lips and inwardly extending passageways downstream of each lip whereby lighter fractions pass to said second portion and to said second outlet and heavier fractions pass to said first outlet.

19. The apparatus described in claim 18 wherein said duct and said partition are so shaped as to form a passageway of decreasing cross-section between said inlet and said first outlet.

26. The apparatus described in claim 18 wherein said duct and said partition are so shaped as to form a passageway of decreasing cross-section between said inlet and said first outlet; and means for controlling the rate of flow through at least one of said outlets.

21. The apparatus described in claim 18 wherein said duct and said partitions are so shaped as to form a passageway of decreasing cross-section between said inlet and said first outlet; means for constricting said first outlet; a chamber receiving the heavier fractions from said first outlet and of sufficient size to convert the kinetic fluid energy to potential energy; and an outlet from said chamber. p

22. In a fluid suspension separator or classifier, a duct forming a passageway and having a fluid inlet at one end, a first outlet at the other end, and a second outlet at said other end; a fluid separating partition within said duct dividing said duct into a first portion connected to said inlet and said first outlet and a second portion connected to said second outlet, said partition including an assembly of spaced elements each having a wall facing the suspension arriving from said inlet forming a transverse concave surface terminating downstream in an outwardly extending lip, the spaces between adjacent elements forming passageways between said first and second portions of said passageways; and means supporting said elements in said duct.

23. In a fluid suspension separator or classifier, a duct forming a passageway and having a fluid inlet at one end; a first outlet at the other end; a second outlet at said other end; a fluid separating partition within said duct and dividing said duct into a first portion connected to said inlet and said first outlet, and a second portion connected to said second outlet; perforations through the wall of said partition; and means for imparting like electrical charges to the particles in the suspension and to said fluid separating partition.

24. In a fluid suspension separator or classifier, means forming a passageway having a fluid inlet at one end and first and second outlets at the other end, separating means within said passageway dividing said passageway into a first portion connected to said inlet and first outlet and a second portion connected to said second outlet and having at least one aperture therethrough providing fluid communication between said first and second portions, and means for imparting like electrical charges to the particles. in the suspension and to said-separating means.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Brown Aug. 29, 1882 Knickerbocker May 8, 1888 Fulweiler Apr. 13, 1937 Van Tongeren Mar. 28, 1939 Van Tongeren Dec. 2, 1941 Haber Sept. 5, 1944 

1. IN A FLUID SUSPENSION SEPARATOR OR CLASSIFIER, A DUCT FORMING A PASSAGEWAY AND HAVING A FLUID INLET AT ONE END; A FIRST OUTLET AT THE OTHER END; A SECOND OUTLET AT SAID OTHER END; A FLUID SEPARATING CORE WITHIN SAID DUCT AND DIVIDING SAID DUCT INTO AN EXTERIOR PORTION CONNECTED TO SAID INLET AND SAID FIRST OUTLET, AND A CENTRAL PORTION CONNECTED TO SAID SECOND OUTLET; PERFORATIONS THROUGH THE WALL OF SAID CORE; AND TRANSVERSELY CONCAVE FACED DEFLECTORS ON THE OUTSIDE OF SAID CORE, ON THE UPSTREAM SIDE OF SAID PERFORATIONS, TO DEFLECT HEAVIER PARTICLES AWAY FROM SAID PERFORATIONS WHILE PERMITTING LIGHTER FRACTIONS TO PASS THERETHROUGH. 